CA1325961C - Viscoelastic cleaning compositions - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A thickened aqueous cleaning composition is viscoelastic, and has utility as a drain opening composition or as a hard surface cleaner having a cleaning-effective residence time on non-horizontal surfaces. In one embodiment the composition comprises a cleaning active, a quaternary ammonium compound, and an organic counterion. In another embodiment, the viscoelastic quality of the composition is advantageously utilized as a drain opener which rapidly penetrates standing water with minimal dilution to deliver active to the clog material.

Description

325q6 1 ~:
VISCOELASTIC CLEANING COMPOSITIONS
AND METHODS OF USE THEREFOR

BACXGROUND OF THE INVENTION
Thifi- i8 a divisi~na~ ~ Canad-ia~ ~atent- Applieati~n Seri~l nulDber 577,717 f}led 5eptember- 16, 19 l. Field of The Invention:

The present invention relates to thickened cleaning compositions having a viscoelastic rheology, and in particular to such thickened cleaning compositions having a viscoelastic -~-~
rheology which are formulated to have utility as drain -cleaners, or which are formulated to have utility as hard --~
surface cleaners. -----.. , -, . :.-2. Description of Related Art: -:, , , :., ' Much art has addressed the problem of developing a thickened -cleaning composition, which may contain a bleach and may have --utility as a hard surface cleanser. The efficacy of such compositions is greatly improved by viscous formulations, increasing the residence time of the cleaner. Splashing ...
during application and use is minimized, and consumer ;
preference for a thick product is well docum~nted. SchilP, U. S. 4,337,163 shows a hypochlorite thickened with an amine ~ oside or a quaternary ammonium compound, and a saturated fatty ¦ acid soap. Stoddart, U. S. 4,576,728 shows a thickened l~ 30 hypochlorite including 3- or 4- chlorobenzoic acid, - 4-bromobenzoic acid, 4-toluic acid and 3-nitrobenzoic acid in combination with an amine o~ide. DeSimone, U. S. 4,113,645 discloses a method for dispersing a perfume in hypochlorite using a quaternary ammonium compound. Bentham et al, U. S.
4,399,050, discloses hypochlorite thickened with certain carboxylated surfactants, amine oxides and quaternary ammonium compounds. JeffreY et al, GB 1466560 shows bleach with a soap, surfactants and a quaternary ammonium compound. For ~; various reasons, the prior art thickened hypochlorite compositions are not commercially viable. In many instances, ., ~ .
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thickening is insufficient to provide the desired residence time on non-horizontal surfaces. Adding components/ and/or modifying characteristics of dissolved components often creates additional problems with the composition, such as syneresis, which require adding further components in an attempt to correct these problems. Polymer thickened -~
hypochlorite bleaching compositions tend to be o~idized by the hypochlorite. Prior art thickened bleach products generally ezhibit phase instability at elevated (above about 100F) and/or low (below about 3SF) storage temperatures.
Difficulties e~ist with colloidal thickening agents in that these tend to e~hibit either false-bodied or thixotropic rheologies, which, at high viscosities, can result in a tendency to set up or harden. Other hypochlorite compositions of the prior art are thickened with surfactants and may ~ -e~hibit hypochlorite stability problems. Surfactant thic~ening systems also are not cost effective when used at the levels necessary to obtain desired product viscosity values. EuroFean Patent Application 0,204,479 published Decem~er 10, 1986 to Stoddard describes shear-thinning compositions, and seeks to avoid viscoelasticity in such shear-thinning compositions.
Drain cleaners of the art have been formulated with a variety of actives in an effort to remove the variety of materials which can cause clogging or restriction of drains.
Such actives may include acids, bases, enzymes, solvents, - -reducing agents, osidants and thioorganic compounds. Such compositions are exemplified by U. S. patents 4,080,305 issued to Holdt et al; 4,395,344 to Maddo~; 4,587,032 to Roqers;
4,540,506 issued to Jacobson et al; 4,610,800 to ~urham et al;
and EuroFean Patent ApplicatiQns 0,178,931 and 0,185,528, publiQhed April 23 and June 25, 1986 respectively, both to ~nn et al. Generally,workers in this field have directed thei~ efforts ~rd actives, or combmations of actives, which would have improved efficacy or speed when used on typically-encountered clog materials; or are safer to use.
- A problem with this approach, however, is that regardless of the effectiveness of the active, if ~he composition is not fully delivered to the clog, the effectiveness of the active . .. . . . - -: . . . ., - - . : - ~ . . -, . - - . -. -. - : ~ : - . - -., . . -. . ~ -.

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will be diminished or destroyed. This is particularly apparent where the clogged drain results in a pool of standing water, and a drain opener composition added to such standing water will be substantially diluted thereby. The above European Patent Applications of Swann et al disclose an attempt to overcome the delivery problem by encapsulating actives in polymeric beads. The Rogers and Durham et al patents refer to the delivery problem and mention that a thickener is employed to increase the solution viscosity and mitigate dilution. Similarly, a thickener is optionally ~ -included in the formulation of Jacobson et al.
I
' SUMMARY OF THE PRESENT INVENTION
: -In view of the prior art, there remains a need for a thickened cleaning composition with a viscoelastic rheology, enabling its use as a drain cleaning composition. There further remains a need for a viscoelastic, thickened cleaning composition which is bleach and phase-stable, even at high viscosities and low temperatures, and can be economically ' formulated.

It is therefore an object of the present invention to provide a viscoelastic, thickened cleaning composition.

It is another object of the present invention to provide a cleaning composition having utility as a drain cleaner by virtue of a viscoelastic rhPology.
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It is yet another object of the present invention to provide a drain cleaning composition which is highly effective.

- I~ is yet another object of the present invention to provide a -visGcelastic thickened cleaning composition which is phase-stable during normal storage, and at elevated or very low temperatures, even in the presence of bleach.
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-~- 1325961 .
It is another object of the present invention to provide a stable thickened hypochlorite composition with a viscoelastic rheology.
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It is another object of the present invention to provide a viscoelastic thickening system which is effective at both high and low ionic strength. -.
It is another object of the present invention to provide a cleaning composition having a viscoelastic rheology to simplify filling of containers during manufacturing, and to facilitate dispensing by the consumer.

Briefly, a first embodiment of the present i:vention comprises a stable cleaning composition having a viscoelastic rheology comprising, in aqueous solution:
(a~ an active cleaning compound;
(b) an alkyl quaternary ammonium compound with the alkyl group at least 14 carbons in length; and (c) an organic counterion.

It should be noted that as used herein the term "cleaning~
refers generally to a chemical, physical or enzymatic treatment resulting in the reduction or removal of unwanted ` material, and ~cleaning composition~ specifically includes drain openers, hard surface cleaners and bleaching ; compositions. The cleaning composition may con~ist of a variety of chemically, physically or enzymatically reactive active ingredients, including solvents, acids, bases, oxidants, reducing agents, enzymes, detergents and thioorganic compounds. `~ :
Viscoelasticity is imparted to the cleaning composition by a system including a quaternary ammonium compound and an organic counterion selected from the group consisting of alkyl and aryl carboxylates, alkyl and aryl sulfonates, sulfated alkyl .

- 1325~61 and aryl alcohols, and mi~tures thereof. The counterion may include substituents which are chemically stable with the active cleaning compound. Preferably, the substituents are ; alkyl or alko~y groups of 1-4 carbons, halogens and nitro groups, all of which are stable with most actives, including hypochlorite. The viscosity of the formulations of the present invention can range from slightly greater than that of water, to several thousand centipoise (cP). Preferred from a - consumer standpoint is a viscosity range of about 20 cP to lOOOcP, more preferred is about 50 cP to 500 cP.
' A second embodiment of the present invention is a composition and method for cleaning drains, the composition comprising, in aqueous solution:
(a) a drain opening active;
(b~ a viscoelastic thickener.

The composition is utilized by pouring an appropriate amount into a clogged drain. The viscoelastic thickener acts to hold the active components together, allowing the solution to travel through standing water with very little dilution. The viscoelastic thickener also yields increased percolation times through porous or partial clogs, affording longer reaction times to enhance clog removal.
.,.:' In a third embodiment the present invention is formulated as a ~
thickened hypochlorite-containing composition having a ~ -viscoelastic rheology, and comprises, in aqueous solution:
(a) a h~pochlorite bleach;
(b) an alkyl guaternary ammonium compound with the alkyl group at least 14 carbons in length; and ~c) a ble3ch-stable organic counterion.
:
.' . In a further aspect, the present invention relates to a method of cleaning restrictions-caused by organic materials in drain pipes comprising (a~ introducing lo a drain pipe , . . ~ .: . : ................... :: - . -. - : . , - ~ - . . . : :

-5a- 1 325961 having an organic restriction therein a drain opening composition comprising a drain opening active and a viscoelastic thickening system wherein the composition has a relative elasticity of greater than about 0.03 sec/Pa a delivery percentage of above about 75%, as determined by pouring a first quantity of composition through a second quantity of standing water and measuring an amount of undiluted product delivered, and a flow rate of less than about 150 mL/minute through a U.S. 230 mesh screen;
(b) allowing the composition to remain in contact with the organic restriction material to react therewith and (c) rinsing the composition and restriction away.

Optionally in any embodiment an amine oxide or betaine surfactant may be included for increased thickening and ~, improved low temperature phase stability.

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It is an advantage of the present invention that the cleaning - composition is thickened, with a viscoelastic rheology.
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It is another advantage of the present invention that the viscoelastic thickener is chemically and phase-stable in the presence of a variety of cleaning actives, including hypochlorite, and retains such stability at both high and low temperatures.

It is another advantage of the present invention that the viscoelastic thickener yields a stable viscous solution at relatively low cost.
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- It is another advantage of the present invention that, when formulated as a drain cleaner the composition travels rapidly through standing water with minimal dilution, improving the efficacy of the cleaner.
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It is another advantage of the present invention that the `
improved efficacy resulting from the viscoelastic rheology allows for safer drain cleaning formulations with lower levels of, or less toxic, actives.

It is a further advantage of the present invention that the ` viscoelastic thickener is effective at both high and low ionic - strength.

It is a further advantage of the composition of the present invention that the viscoelasticity facilitates container -~
filling, and dispensing, by reducing dripping.

It is yet another advantage of the composition of the present -- invention that thickening is achieved with relatively low levels of s~rfactant, improving chemical and physical ; stability.

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These and other objects and advantages of the present invention will no doubt become apparent to those skilled in the art after reading the following Detailed Description of the Preferred Embodiments.

DETAILED DESCRIPTION OF THE PREFE~RED EMBODIMENTS
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In a first embodiment, the present invention is a-thickened ; viscoelastic cleaner comprising, in aqueous solution;
~a) an active cleaning compound;
(b) an alkyl quaternary ammonium compound with the alkyl group at least 14 carbons in length; and (c) an organic counterion;
, Active Cleaning Compounds A number of cleaning compounds are known and are compatible , - with the viscoelastic thickener. Such cleaning compounds ' 20 interact with their intended target materials either bys chemical or enzymatic reaction or by physical interactions, which are hereinafter collectively referred to as reactions.
Useful reactive compounds thus include acids, bases, osidants, reductants, solvents, enzymes, thioorganic compounds, surfactants ~detergents) and mistures thereof. Examples of useful acids include: carbo~ylic acids such as citric or acetic acids, weak inorganic acids such as boric acid or - sodium bisulfate, and dilute solutions of strong inorganic acids such as sulfuric acid. Examples of bases include the 3 alkali metal hydrosides, carbonates, and silicates, and specifically, the sodium and potassium salts thereof.
Oxidants, e.g., bleaches are a particularly preferred cleaning active, and may be selected from various halogen or perosygen bleaches. E~amples of suitable perosygen bleaches include hydrogen peroxide and peracetic acids. Esamples of enzymes ` include proteases, amylases, and cellulases. Useful solvents -~ include saturated hydrocarbons, ketones, carboxylic acid esters, terpenes, glycol ethers, and the li~e. Thioorganic - ' ~' '~

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compounds such as sodium thioglycolate can be included to help break down hair and other proteins. Various nonionic, anionic, cationic or amphoteric surfactants can be included, - as known in the art, for their detergent properties. Examples include taurates, sarcosinates and phosphate esters.
Preferred cleaning actives are o~idants, especially hypochlorite, and bases such-as alkali metal hydro~ides. Most preferred is a mi~ture of hypochlorite and an alkali metal hydro~ide. The cleaning active as added in a cleaning-effective amount, which may range from about 0.05 to 50 percent by weight, depending on the active.

Quaternary Ammonium Compound :
The viscoelastic thickener is formed by combining a compound having a quaternary nitrogen, e.g. quaternary ammonium - ~ ~
compounds (quats) with an organic counterion. The quat is ~ :
selected from the group consisting of those having the following structures:

(i) Rl R4-l-R2 i R3 wherein Rl, R2 and R3 are the same or different, and are methyl, ethyl, propyl, isopropyl or benzyl, and R4 is C14-18;

~ R5 a~d;

wherein R5 is C14 18 alkyl, and;

(iii) mi~tures thereof.
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Most preferred, especially if ionic strength is present, is a C14_18 alkyl trimethyl ammonium chloride and especially cetyltrimethyl ammonium chloride (CETAC). It is noted that when referring to carbon chain lengths of the quat or any other compound herein, the commercial, polydisperse forms are contemplated. Thus, a given chain length within the preferred C14 18 range will be predominately, but not e2clusively, the specified length. The pyridinium and ~enzyldimethyl ammonium headgroups are not preferred if ionic strength is high. Also, 10 it is preferred that if Rl is benzyl, R2 and R3 are not benzyl. Commercially available quats are usually associated with an anion. Such anions are fully compatable with the counterions of the present invention, and generally do not detract from the practice of the invention. Most typically, the anion is chloride and bromide, or methylsulfate. Where the cleaning active includes hypochlorite, however, the bromide anion is not preferred.
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The quaternary ammonium compound is added at levels, which, when combined with the organic counterion are thickening ; effective. Generally about 0.1 to 10.0 weight percent of the quaternary ammonium compound is utilized, and preferred is to use about 0.3 to 3.0% quat.
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; Organic Counterion . .
The organic counterion is selected from the group consisting f C2 10 alkyl carbo~ylates, aryl carbo~ylates, C2 10 alkyl sulfonates, aryl sulfonates, sulfated C2 10 alkyl alcohols, sulfated aryl alcohols, and mi2tures thereof. The aryl compounds are derived from benzene or napthalene and may be substituted or not. The alkyls may be branched or straight ~hain, and preferred are those having two to eiqht carbon - atoms. The counterions may be added in acid form and converted to the anionic form in situ, or may be added in anionic form. Suitable substituents for the alkyls or aryls are Cl 4 alkyl or alkoxy groups, halogens, nitro groups, and mi2tures thereof. Substituents such as hydro~y or amine .

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groups are suitable for use with some non-hypochlorite cleaning actives, such as solvents, surfactants and enzymes.
If present, a substituent may be in any position on the rings.- If benzene is used, the para (4) and meta (3) positions are preferred. The counterion is added in an amount sufficient to thicken and result in a viscoelastic rheology, - and preferably between about 0.01 to lO weight percent. A
preferred mole ratio of quat to counterion is between about 12:1 and 1:6, and a more preferred ratio is about 6:1 to~l:3.
Without limiting to a particular theory, it is thought that the counterion promotes the formation of elongated micelles of the quat. These micelles can form a network which results in efficient thickening. It has been suprisingly found that the viscoelastic thickening as defined herein occurs only when the counterion is minimally or non surface-active. E~perimental data shows that, generally, the counterions of the present invention should be soluble in water. Surface-active counterions normally don't work, unless they have a have a ` 20 critical micelle concentration (CMC) greater than about 0.1 molar as measured in water at room temperature 5about 70F).
Counterions having a CMC less than this are generally too insoluble to be operable. For example, sodium and potassium salts of straight chain fatty acids (soaps), having a chain length of less than ten carbons, are suitable, however, longer chain length soaps generally don't work because their CMC's are less than about 0.1 molar. See Milton J. Rosen, Surfactants and Interfacial Phenomena, John Wiley and Sons.

Table 1 shows the effect on viscosity and phase stability of a number of different counterions. The quat in each example is OE TAC, and about 5.5-5.8 weight percent sodium hypochlorite, 4-5 weight percent sodium chloride, and about 1.4-l.9 weight percent sodium hydroxide are also present.
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1 325q6 1 - ' Table I. Effect of Counter;ons No. Viscos;ty Nu~ber of Phases Counterion (cP) at Indicated Temp. (-F) CETAC
Wt.Z Vt.Z Name 3rpm3ûrpm 12 3û 107 71 lZ7 1 0.50 None - 14 2 2 2 û.50 O.ûlû Acetic Acid 90 74 2 2 -3 O.SO 0.200 Acetic Acid lû0 81 2 2 4 0.50 0.050 8utyric Acid 100 76 O.Sû 0.450 Butyric Acid 40 38 2 2 6 0.50 0.050 Octanoic Acid 50 40 7 0.50 0.200 Octanoic Acid 80 74 8 0.50 0.050 Sodium Octylsulfonate 220 165 2 2 9 0.50 0.100 Sodium Octylsulfonate 280 229 2 2 0.75 0.150 Sodium Oc~ylsulfonate 400 353 2 2 11 0.48 0.180 Benzoic Acid - 2 2 12 0.48 0.170 4-Tolu;c Acid 10 14 lC 1 1 1 -13 0.22 0.200 4-Chlorobenzoic Acid400 135 2 2 14 0.30 0.300 4-Chlorobenzoic Acid960 202 2 2 0.50 0.050 4-Chlorobenzoic Acid380 213 2 2 16 0.50 0.12S 4-Chlorobenzoic Acid2010 507 17 0.50 0.200 4-Chlorobenzoic Acid4450 850 2 2 18 0.50 0.250 4-Chlorobenzoic Acid4180 820 19 0.50 0.375 4-Chlorobenzoic Acid 5530 1000 O.SO 0.500 4-Chlorobenzoic Acid4660 770 22 O.SO 0.625 4-Chlorobenzoic Acid3180 606 23 O.SO 0.750 4-Chlorobenzoic Acid1110 341 24 0.50 0.875 4-Chlorobenzoic Acid170 125 S 0.50 1.000 4-Chlorobenzoic Acid30 20 26 0.70 0.100 4-Chlorobonzoic Ac;d250 167 2 2 27 0.70 0.300 4-Chlorobenzoic Acid4640 791 2 2 28 0.78 0.200 4-Chlorobenzoic Acid3110 622 2 2 29 1.20 0.300 4-Chlorobenzoic Acid940 685 2 0.50 0.200 2-Chlorobenzoic Acid 10 7 2 31 0.50 0.200 2,4-Dichlorobenzoic Acid 1920 65d 2 1 1 1 32 û.S0 û.200 4-Nitrobenzoic Ac;d10 19 2 33 0.48 0.210 Salicylic acid1040359 lC lC 1 1 1 34 0.50 0.150 Naphthoic Ac;d750306 2 lC
0.50 0.030 Phthalic acid70 73 2 2 36 0.S0 0.400 Phthalic acid 8û 64 2 2 1 1 1 ~ : ' .

; Table I. Effect of Counterions (cont d) i - Number of Phases ; No. Viscosity at Indicated Temp. (-F) Counterion (cP) -CETAC
Wt.X~t.Z Hame 3rpm 30rpm 12 30 107 71 127 37 O.Sû O.lOû ben2enesulfonic Acid 40 46 2 2 38 0.50 0.2ûO ben2enesulfonic Acid 150 122 2 2 39 0.50 0.4ûO Sen2enesulfonic Acid 220 175 2 lC 1 O.S0 0.100 Toluenesulfonic Ac;d 36û 223 2 2 41 O.S0 0.200 Toluenesùlfonic Acid 370 260 2 2 42 0.50 0.300 Toluenesulfonic Acid 290 238 2 /
43 0.50 û.150 Sodium Cumènesulfonatethick 2 44 O.S0 û.030 Sodium XylenesulfonatelSû 119 2 2 2 0.50 0.100 Sodium Xylenesulfonate610 279 2 46 0.50 0.150 Sodium Xylenesulfonate260 224 2 47 0.50 û.200 Sodium Xylenesulfonate130 123 2 2 48 0.97 0.630 Sodium Xylenesulfonate100 120 lC 1 1 2 2 49 0.50 0.050 4-Chloroben2enesulfonate lS0 118 2 2 50 0.50 0.100 4-Chlorobenzenesulfonate 420 248 2 lC
Sl- O.S0 0.200 4-Chlorobenzenesulfonate 140 149 2 2 .~. .
52 0.50 0.050 Methylnaphthalenesulfonate 290 202 2 2 53 O.S0 0.100 Hethylnaphthalenesulfonate 220 208 2 2 54 0.7û 0.150 Methylnaphth21enesulfonate 480 390 2 2 :1 , .
:
CETAC . Cetyltr;nethylammonium Chloride.
All formulas cont~;n 0.113 wt.X of sodiun silicate (SiO2~Na20 . 3.22);
5.5-5.8 X sodium hypochlorite 4.3-4.7 ~t. X sod;um chloride ~nd 1.4-1.9 wt.X
sodium hydro~ide.
Viscosities ~ere neasured at 72 - 81-F with a Orookfield rotovisccmeter nodel LVTD using spindle #2.
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30 C . Cloudy :':
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1 325~6 1 Examples lS-25 and 44-47 of Table I show that viscosity depends on the ratio of counterion to quat. When the quat is CETAC and the counterion is 4-chlorobenzoic acid, maximum viscosity is obtained at a quat to counterion weight ratio of about 9:3. With CETAC and sodium ~ylene sulfonate, the ratio is about 5:1 by weight.

Preferred formulations of the present invention utilize a mi~ture of two or more counterions. Most preferably the counterion is a misture of a carbo~ylate and a sulfonate, which surprisingly provides much better low temperature phase stability than either individually. As used herein sulfonate-containing counterions include the sulfated alcohol counterions. This is true even in the presence of ionic strength. Esamples of such miYtures are shown in Table II.
Esamples of preferred carboxylates are benzoate, 4-chlorobenzoate, napthoate, 4-toluate and octanoate.
Preferred sulfonates include xylenesulfonate, 4-chlQrobenzenesulfonate and toluene sulfonate. Most preferred is a mi~ture of at least one of the group consisting of 4-toluate, 4-chlorobenzoic acid and octanoate with sodium xylenesulfonate. A preferred ratio of carbo~ylate to sulfonate is between about 6:1 to 1:6, more preferred is -between about 3:1 to 1:3. ~istures of counterions may also act to synergistically increase viscosity, especially at low ~-ratios of counterion to quat. Such synergism appears in some cases even if one o the counterions results in poor phase stability or low viscosity when used alone. For e~ample, -~
samples 11 and 46 of Table 1 (benzoic acid and sodium ~-~
xylenesulfonate, respectively) yield low viscosities ~2 cP and 224 cP respectively) and are phase instable at 30CF. When -combined, however, as shown by samples 3-5 of Table II. The formulations are all phase-stable even at 0F, and sample 5 shows a much higher viscosity than that of the same components ~-individually. , ,' ' ,''; ~'' .' Table rI~ Effect of Hixed Counterions.

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Viscos;ty No. Counterion Counter;on cP Number of Phases CETAC at Indicated TemD. (F) Vt.Z WtZ Name VtX Name 3rpm 3ûrpm û 12 3û 71 lû7 127 1 O.SO 0.20 Ben20ic Acid 0.2û aSA 170 136 2 2 lC
2 0.50 0.30 8en20ic Acid 0.10 4-CBSA lû70 4û8 lF lC lC
3 0.60 0.24 Ben20ic Acid 0.24 SXS 18C 173 lF lC
4 0.6Z 0.10 Benzoic Ac;d û.32 SXS lûO 74 lC lC
0.62 0.45 Ben20ic Acid û.l5 SXS 690 424 lC lC
6 0.62 0.09 4-CBA 0.20 Ben~oic Acid1340 429 lF lC lC
7 0.62 0.09 4-CBA 0.3û p-Toluic Acid 7680~ 2440 2 2 2 8 0.62 0.09 4-C8A 0.20 2-C9A 116û 414 lC 2 lC
9 0.62 O.û9 4-C9A û.20 4-NBA 840 387 lC lC
13 0.31 0.05 4-C9A 0.10 Naphtho~c Ac1d 790 29û lF lC
11 0.62 0.09 4-CBA 0.10 Naphthoic Ac1d 3400 lû25 lF lC lC
12 0.62 0.09 4-CBA 0.30 Naphthoic Acid 5560 236û 2 2 13 O.SO 0.10 4-C9A 0.15 Octanoic Ac;d 60 54 14 û.62 O.û9 4-CBA û.20 BSA 241û 695 lF lC lC
0.15 0.05 4-C8A û.05 TSA 140 56 2 2 2 16 0.30 0.10 4-CBA 0.10 TSA 1140 270 Z 2 17 0.50 0.20 4-CBA 0.10 TSA 2520 625 2 2 2 18 0.30 0.08 4-C8A 0.08 SXS 400 142 2 2 19 0.30 0.10 4-C8A û.10 SXS 635 142 2 2 2 1 1 1 -0.30 0.12 4-CBA 0.30 SXS 200 140 lF
21 0.37 0.11 4-CBA û.22 SXS 470 270 2 22 0.48 0.06 4 CBA 0.32 SXS 80 91 lF lC 1 1 1 1 ~-23 0.50 0.10 4-C8A 0.18 SXS 440 344 lF lC
24 0.50 0.10 4-CBA 0.10 SXS 1100 313 2 2 2 0.50 0.12 4-CBA 0.35 SXS 402 320 lF
26 0.50 0.13 4-CBA 0.50 SXS 250 221 lF
27 O.SO O.lS 4-CBA O.lS SXS 47601620 2 2 28 0.50 0.15 4-CBA 0.25 SXS 970 382 2 2 29 O.SO 0.15 4-C8A û.50 SXS 470 350 lF
O.SO 0.38 4-C8A 1.13 SXS 60 45 31 0.69 0.17 4-CBA û.45 SXS 720 576 lC
32 0.69 0.20 4-CBA û.40 SXS 314û ô94 lF
33 0.82 0.13 4-CBA 0.35 SXS 440 450 lF lC
34 0.89 0.09 4-CBA 0.31 SXS 520 531 lC 2 ' .. .. . .

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1 3 2 5 ~ 6 1 Table II. Effect of Mixed Counterions. (Cont d) Viscosity No. Counterion Counterion cP Number of Phases CETAC at Indicated Temo. (-F) Yt.Z VtZ Name VtX Name 3rpm 3ûrpm 0 12 3û 71 107 127 û.9û 0.13 4-C8A û.26 SXS 1950 163û 2 2 36 û.Sû û.lû 2-CBA 0.15 SXS 140 128 lF 2 lC
; 37 0. 2 0.10 2 4-D 0.32 SXS lOû 86 lF lC
38 O.SO 0.10 4-N8A û.20 BSA 310 2û6 lF 2 lC
39 O.SO 0.10 4-NBA0.05 1 C8SA 360 20û lF 2 lC
0.62 0.12 4-NBA 0.32 SXS lOû 95 lF lC
41 0 50 0.20 Phthalic acid 0.10 SXS 180 165 2 2 42 0 15 0.05 Naphthoic Acid O.OS SXS 40 27 lF lC
43 0.20 0.10 Naphthoic Acid 0.10 SXS 90 54 2 lC 1 1 1 1 44 0.40 0.10 Haphthoic Ac;d 0.20 SXS 110 100 lC lC
0.60 0.10 Naphthoic Ac;d 0.20 SXS 340 294 2 2 46 0.62 0.15 Naphthoic Acid 0.32 SXS 160 141 lC lC
47 0.50 0.10 Naphthoic Acid0.10 4-CBSA 1210 356 lF lC 1 1 1 1 48 O.SO 0.15 SXS 0.20 BSA 190 135 2 2 lC
49 0.50 0.04 SXS 0.06 TSA 4ûO 212 2 2 2 0.50 0.12 SXS 0.08 TSA 250 224 2 51 0.50 0.12 SXS 0.18 TSA 170 lSO 2 2 2 52 0.50 0.15 SXS 0.05 4-C3SA 90 82 2 lC
53 0.50 0.05 Octanoic Acid 0.20 SXS 180 166 lF lC
i 54 0.50 0.10 Octanoic Acid 0.15 SXS 310 248 2 lC
i 20 55 0.60 0.15 Octanoic Acid 0.10 SXS 340 283 2 lC lC
56 0.50 0.15 Octanoic Ac;d 0.20 SXS 210 175 lF lC 1 1 1 1 i 57 O.SO 0.20 Octano;c Acid 0.10 SXS 160 135 lF lC
58 0.50 O.û~S Na Octylsulfonate0.06 HNS 200 182 Z 2 2 ,' " . :-, ~ , CETAC . Cetyltr;0ethylam00n;u0 Chlor1de.
All for0ul-s contain 0.113 wt.X of sod1u0 s;l1cate (SiO2 / Na20 . 3.22); 5.6-5.8 ~t. X sod;um hypochlor1te; 4-5 ~t. X sod1u0 chloride and 1.7-1.8 ~t. X sodiu0 hydrox1dQ -~
V1scosit1es ~er~ 0easured at 72 - 81 F ~th a Brookf1eld rotoviscometer model LVTO using spindle #2.
~, 4-CBA . 4-Chlorobenzo;c Acid 4_C8SA - 4-Chlorobenzenesulfonic Ac;d SXS - Sodiu0 Xylenesulfonate 2-CBA 2-Chlorobenzo;c Ac;d BSA . Benzenesulfonic Acid 2 1 0 . 2 4-Oichlorobenzoic Acid TSA ~ Toluenesulfonic Acid 4-NBA . 4-Nitrobenzoic Acid HNS . Hethylnaphthalenesulfonate C ~ Cloudy F - Frozel : ':
.,,,~..
..

~.,. ' . ~ .

-16- 1 32 5q 6 Cosurfactants .
Thickening can be enhanced, and low temperature phase stability improved, through the addition of a cosurfactant selected from the group consisting of amine o~ides, betaines and mixtures thereof. The preferred cosurfactants are alkyl dimethyl amine oxides and alkyl betaines. The longest alkyl group of the amine o~ide or betaine generally can be eight to eighteen carbons in length, and should be near the upper end of the range where cosurfactant levels are high. Useful amounts range from a trace (less than about .01~) to an amount aboùt egual to that of the quat. Table III shows the the effect of adding cosurfactants on phase stability and viscosity.
For e~ample, formula 11 in Table III shows that adding 0.04 weight percent of myristyl/cetyldimethylamine o~ide to ~ -formula 19 of Table II about doubles the viscosity and decreases the low temperature phase stability limit by at least 15--degrees. Similar effects are~seen by comparing formulas III-9 and III-10 with II-18 and formula III-12 with II-24. That betaines work as well is demonstrated by ccmparing formulas III-18 and III-l9 with formula II-25. Such behavior is surprising since formulas 26 and 27 in Table III `
and the formulas in Table I show that these cosurfactants do not thicken with only the organic counterions as used in this invention. However, adding too much cosurfactant can decrease viscosity as shown by comparing formulas 3 with 4, and 13 with 14, in Table III.

Table III. Effect of Cosurfactants Number of Phases No. Viscosityat Ind;cated Temp. (-F) Cosurfactant cP

~t.X Vt.Z Name ~t.Z Vt.Z3rpm 3ûrpm û 12 3û 71 lû7 127 ::
1 û.3û û.û2 Lauryl DMAO 0.12 0.22 58û 202 lF
2 û.3û û.04 Lauryl DMAO û.12 û.22 490 226 lF
3 û.Sû û.lû Lauryl DHAO û.2û û 93û 327 2 lC
4 û.SO 0.20 Lauryl DMAO 0.2û 0 20 23 0.24 O.û6 Hyr;styl DMAO 0.080.1448û 165 lF
6 0.24 O.û8 Hyristyl DMAO 0.08~.14530 183 lF
7 0.30 0.03 Hyristyl OMAO O.lû0.18 52û 193 lF
8 0.30 0.06 Hyristyl DMAO û.100.18 760 230 lF
9 0.30 O.lS Myristyl/Cetyl DMAO 0.080.08 940 295 2 2 lC
0.30 0.25 Myristyl/Cetyl ûMAO 0.080.08 750 313 2 2 lC
11 0.30 0.04 Hyristyl/Cetyl ûMAO 0.100.10 1100 223 2 2 12 0.50 0.25 Myr;styl/Cetyl DMAO 0.100.10 3800 779 2 2 lC
13 0.50 0.10 Hyr;styl/Cetyl DMAO 0.20 0 3420 640 lF lC
14 0.50 0.20 Hyr;styl/Cetyl DHAO 0.2û 0 2540 545 û.50 0.10 Lauroyl Sarcosine 0.120.35 380 355 lC
16 O.SO 0.10 Cetoylmethyltaurate 0.120.35 200 196 lC lC 1 2 2 17 O.SO 0.10 Cetoylmethyltaurate û.120.70 230 214 lC lC
18 O.SO 0.10 Cetylbeta;ne 0.120.35580 456 lF lC 1 1 1 2 19 0.5û 0.10 Laurylbeta;ne 0.120.35740 443 0.42 0.08 Dodecyl TAC O.lS û.35 45û 339 21 û.38 û.12 Oodecyl TAC O.lS 0.35 190 180 1 1 ] 1 1 22 0.42 0.08 Coco TAC O.lS 0.35 610 385 23 0.38 0.12 Coco TAC O.lS 0.35 31û 239 24 C 0,50 Oodecyl TAC 0.15 0.35 Thin 0 1.00 ûodecyl TAC 0.30 0.35 Th;n 1 2~ û 0.25 Hyristyl/Cetyl DMAO 0.10 0.10 1 5 lF
27 0 0.5û Laurylbetaine û.15 0.35 1 S
OMAO - D~0ethylamine oxide TAC - Tri0ethylammmonium Chloride CETAC - Cetyltri0ethylammonium Chlor;de 4-C8A - 4-Chloroben~oic Acid SXS - 50diu0 Xylenesulfonate C _ Cloudy F _ Fro2en All for0ulas contain 5.8 wt.X of sodi w hypochlor;te, 1.5 wt.X of sod;um hydroxide, 4.5 wt. X sod; w chloride, 0.25 wt. X sod;um carbonate and 0.113 wt.X of sodium silicate (sio2 /Na20 ~ 3.22) . :---:
Yiscosities were ~easured at 72 - 81 F ~ith a Brookfield rotoviscometer model LVTO using spindle # 2.
:.

In the second embodiment of the present invention a composition suitable for opening drains is provided comprising, in aqueous solution:
- (a) a viscoelastic thickener; and - (b) a cleaning active.

The viscoelastic thicS~ener may be any such thickener yielding viscoelastic properties within the limits set out herein, and - -preferably is of the type as described for the first embodiment herein. Polymers, surfactants, colloids, and mixtures thereof, which impart viscoelastic flow properties to an aqueous solution, are also suitable. The viscoelasticity of the thickener advantageously imparts unusual flow properties to the cleaning composition. Elasticity causes the stream to break apart and snap back into the bottle at the end of pouring instead of forming syrupy streamers. Further, elastic fluids appear more viscous than their viscosity indicates. Instruments capable of performing oscillatory or controlled stress creep measurements can be used to ~uantify elasticity. Some parameters can be measured directly (see Hoffmann and Rehage, Surfactant Science Series, 1987, Vol. 22, 299-239 and EP 204,472), or they can be calculated using models. Increasing rela~ation times indicate increasing elasticity, but elasticity can be moderated by increasing the - ~-resistance to flow. Since the static shear modulus is a measure of the resistance to flow, the ratio of the relaxation time ~Tau) to the static shear modulus (G0) is used to measure relative elasticity. Tau and G0 can be calculated from oscillation data using the Ma~well model. Tau can also be calculated by taking the inverse of the frequency with the maximum loss modulus. G0 is then obtained by dividing the complex viscosity by Tau. To obtain the full benefits of the viscoelastic thickener, the Tau/G0 (relative elasticity) should be greater than about 0.03 sec/Pa.

' ':

" . ' '.' .- ~'.' . ' ' . - ' . ' : ~: ' ,' ' '. : , , .' ' ' ' ' . : , ': :
.: ' ' .' . '. ,. ,, ' ' . , . ., . .. . . , ', ': . : ,'.' ' . ' ' , ' : . , : ' -19- 1 325q61 Some consumers do not like the appearance of elastic flow properties. Thus, for certain products the elasticity should be minimized. It has been empirically determined that good - consumer acceptance is usually obtained for solutions with Tau/G0 less than about 0.5 sec/Pa, although much higher relative elasticities can be formulated. The relative elasticity can be varied by varying the types and concentrations of quat and counterions, and by adjusting the relative concentrations of counterions and quat.
~, .
- Table IV shows the effect of composition on rheology and corresponding drain cleaning performance. The latter is measured by two parameters: (1) percentage delivery; and (2) flow rate. Percentage delivery was measured by pouring 20 mL
of the composition, at 73 F, into 80 mL of standing water, and measuring the amount of undiluted product delivered. Flow rate was measured by pouring 100 mL of the composition through a No. 230 US mesh screen and recording the time to pass through the screen. A delivery of 0% indicates that only diluted product, if any, has reached the clog; a 100% delivery indicates that all of the product, substantially undiluted, ~as reach~d the clog. Rheology was measured with a Bolin VOR
rheometer at 77 F in the oscillatory mode. The viscosity ~-is the in-phase component extrapolated to 0 ~erz. The rela~ation time, Tau, and the static shear modulus, G0, were calculated using the Maxwell model. The ratio Tau/G0 is, as previousl~ described, postulated to be a measure of relative elasticity.
-~

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,- . : :.. ... .... :: . .. - -. : .. - -- ., .- . - - . . - . . . ..

--.. - :. .. . . : . , .... . ~ : , .
. . ~ -. , . - - . . . . . . : :. .

-~a- 1 3 2 5 ~ 6 1 Table IV. Effect of Composit;on on Rheology and Orain Opener Performance.

No. CETAC SXS Cou~terion Viscosity Tau Gû Tau/Gû Delivery Flow Rate _ ~ItX Wt% Vt% TvDecP sec Pa sec/Pa X mL/min 1 û.370 0.260 0.080C8A 47 0.33 0.930.35 2 0.500 0.1430.071 C8A 247 0.84 1.860.45 96 46 3 0.500 0.2860.071 C8A 84 0.20 2.660.08 73 150 4 0.500 0.350 û.12û C8A 153 0.47 2.110.22 96 33 0.500 0.3150.132 C8A 560 1.29 1.830.71 ~ 6 0.625 0.1250.063 CBA 716 2.00 2.250.89 96 27 3 7 0.625 0.2500.063 C8A 14û 0.23 3.940.06 ~4 109 ?, 10 8 0.625 0.313 û.l56 C~A 390 0.67 3.650.18 96 26 9 0.625 0.6250.156 C8A 302 0.53 3.630.15 86 33 0.670 0.3100.085 CaA 142 0.20 4.560.04 - 43 11 0.750 0.225O.O~S C8A 327 0.44 4.770.09 87 67 12 0.750 0.2140.107 C8A 478 0.66 4.570.14 9S 34 13 0.750 0.4280.107 CaA 147 0.16 5.680.03 78 lûO
14 0.750 0.562 û.188 C8A 587 0.69 5.360.13 94 27 0.100 O.OSOO.OSO NA 7 0.08 0.230.35 74 133 - 16 0.150 O.OSO0.050 NA 26 0.26 0.261.00 82 80 17 0.200 0.100O.OSO NA 21 0.64 0.222.91 90 120 18 0.20û 0.100 0.100NA 43 0.98 0.244.08 90 46 19 0.400 0.2000.100 NA 71 0.42 1.070.39 94 52 0.6ûO 0.200 0.100NA 244 0.60 2.640.23 97 27 .:
21 0.400 0.1300.160 ~A 116 0.83 0.830.99 91 48 22 :0.500 0.2ûO 0.290 8A 166 0.73 1.41 0.5294 32 23 0.600 0.2400.160 8A 94 0.27 2.320.12 81 71 24 0.600 0.3000.380 8A 128 0.36 2.320.16 93 34 -0.600 0.2500.150 TA 137 0.26 3.220.08 91 63 .l 26 0.600 0.4000.150 TA 46 0.13 2.200.06 68 109 27 0.600 0.4000.300 TA 178 0.42 2.620.16 93 36 CETAC ~ Cetyltri0ethylammonium Chloride; SXS - Sodium Xylen0sulfonate; CBA .
4-Chloroben20ic Acid; NA _ l-Naphthoic Acid; 8A ~ 80n20ic Ac~d; TA . 4-Toluic Acid.
A11 fonmulas contain 5.8 wt.X sodium hypochlorite NaOCl, 4.55 wt.X Cl sodium cchloride, 0.25 wt.X sodiu~ carbonate, 1.5 wt.Z sodium hydroxide, and 0.113 wt.X of sodium silicat2 (SiO/Na20 - 3.22).

The viscoelastic compositions herein represent a substantial departure from compositions of the prior art in that elasticity, rather than simply viscosity, is the crucial parameter to the success of the invention. The viscoelastic thickener provides surprising advantages when formulated as a drain cleaner. Because the elastic components hold the solution together, it will travel through standing water with very li~tle dilution, delivering a high percentage of active - to the clog. The elasticity results in a higher delivery rate of active than a purely viscous solution of the same viscosity. This is true even if the viscosity of the solution is low. Thus, viscosity alone will not result in good performance, but elasticity alone will, and a solution which is elastic and has some viscosity will result in superior performance. Such purely viscous solutions, furthermore, do - not achieve their highest delivery rates unless the viscosity is very high (above about 1000 cP). This presents other probiems, including difficulty in dispensing at low temperatures, poor penetration into clogs, reduced consumer acceptance, and high cost associated with attaining such high viscosities. The elasticity also yields increased percolation times through porous or partial clogs, surprisingly increasing `
the effectiveness of a drain opening composition.

Table V compares psrformance vs. rheology for five formulations: an unthickened control, a sarcosinate, non-viscoelastic thickened formulation, a slightly viscoelastic formulation of a surfactant and a soap, and two viscoelastic formulations of the present invention. The delivery and flow rate parameters were measured as in Table IV.

- .. . . .- : . - . ~ .- , .

. ~
. . - : :- :

- 1 325q61 .'-Table V. Perfor~ance Versus Rheology .
; Formula RheoloqvViscos;tvTau G0 Tau/60 Oelivervb n ow RateC
: cP secPa secJPa Z 0L/m;n 1 unthickened 1 3 O 0 9 2400 2 thickened nonelastic141 a.l2 7.640.016 6 92 3 smooth 334 0.35 6.060.058 47 52 4 elastic 14~ 0.26 3.480.075 93 SS
elastic lS3 0.47 2.110.223 96 33 .
b.- Percentage of product that passes through standing water to the clog.
Twenty mL of product at 73 F was poured into 83 mL of standing water.
c. Rate of F1OW for product at 73 F through a 230 mesh SiQVe.

E9~-:LL~ ~t.ZComoound Wt.X Comoound Wt.XComDound 1 contains no thickeners .; 2 1.6 HOMAO 0.37 Sarcosinate~l)O.û3 Pri0acor 598û(2) 3 0.8 MOMAO 0.25 Lauric Acid - -4 0.62 CETAC O.O9 4-CdA û.29 SXS
S 0.50 CETAC .12 4-CaA 0.35 SXS

(1) Sodium lauroyl sarcosinate ~2) A trade0arked product of the Dow Che~ical Co., comprising a copoly0er of , acrylic ac;d and ethylene All for0ulas contain 5.8 wt. X sodiu0 hypochlor;te, 1.75 wt. Z sodium hydroxide and O.ll wt. Z sodium silicate (SiO2/Na2û . 3.22).
i MOHAO ~ Myristyldi0ethylamine oxide CETAC - Cetyltri0ethyl a0mon;u~ chlorids 4-C~A . 4-chloroben20ic ac~d SXS ~ Sod;u0 Xylenesulfonat8 :: :

~"~

- :
.
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.. ,. ~ . ~ -, ~ . . - .. .. . -.. -. . . - - : :. . .
:. . , . ~ .- .. : . - - - : ,: -. . . : .:

-23- 1 325~6 1 From Table V, it can be seen that formulas 1 and 2, which are not viscoelastic, have very low delivery values and high flow rates. This is true even though formula 2 is moderately thickened. The formulas of Table IV show that at a Tau/G0 of about .03 or greater, a preferred delivery percentage of above about 75% is attained. More preferred is a delivery percentage of above about 90%. Thus, relative elasticities of above about 0.03 sec/Pa are preferred, and more preferred are values of above about 0.05 sec/Pa. A most preferred relative elasticity is above about 0.07 sec~Pa. A preferred flow rate is less than about 150 mL/minute, more preferred is less than about 100 mL/minute. It can also be seen from Tables IV and V
that the relative elasticity of the composition, rather than viscosity, is crucial to drain opener performance. Comparing, for e~ample, formulas 3 with 4 of Table V, shows that despite having only about half the viscosity, formula 4, with a slightly higher relative elasticity, far outperformed formula 3. ~Formulas 15 and 17 of Table IV also show that low viscosity formuIas can display good drain opening performance as long as sufficient relative elasticity is present.
, ' . :
- It is noted that viscosities reported herein are shear viscosities, i.e. those measured by a resistance to flow perpendicular to the stress vector. However, the parameter ~hich most accurately defines the rheology of the present invention is extensional viscosity, i.e. uniaxial resistance to flow a~ong the stress vector. Because a means of directly measuring extensional viscosity in solutions as described herein is not yet available, the relative elasticity parameter (Tau/G0) is used as an approximation. It is noted that if a means of measuring extensional viscosity becomes available, such means could be used to further define the scope of the present invention.

--- , ", ,,,, ,. . , ~ . . . . .

1 32sq6 1 The maximum benefits of the viscoelastic rheology of the drain cleaning composition of the present invention are attained when the composition is denser than water, enabling it to penetrate standing water. While less dense compositions still benefit from the viscoelastic rheology when applied to drains having porous or partial clogs, the full benefit is obtained when the composition possesses a density greater than water.
In many instances, this density is attained without the need for a densifying material. In formulations containing sodium hypochlorite, for example, sufficient sodium chloride is present with the hypochlorite to afford a density greater than water. When necessary to increase the density, a salt such as sodium chloride is preferred and is added at levels of 0 to about 20~.

The cleaning active is an acid, base, solvent, oxidant, reductant, enzyme, surfactant or thioorganic compound, or mixtures thereof, suitable for opening drains. Such materials include those as previously described in the first embodiment which act by either chemically reacting with the clog material to fragment it or render it more water-soluble or dispersable, physically interacting with the clog material by, e.g., adsorption, a~sorption, solvation, or heating (i.e. to melt grease), or by enzymatically catalyzing a reaction to fragment or render the clog more water-soluble or dispersable.
- Particularly suitable are alkali metal hydroxides and hypochlorites. Combinations of the foregoing are also suitable. The drain opener may also contain various adjuncts as known in the art, including corrosion inhibitors, dyes and fragrances.

A preferred example of a drain cleaning formulation includes:
(a) an alkyl quaternary ammonium compound having at least a C14 alkyl group;
(b) an organic counterion (c) an alkali metal hydro~ide;
~d) an alkali metal silicate;

: - - ~ : - : -, , -- :

1 325~6 1 (e) an alkali metal carbonate; and (f) an al~ali metal hypochlorite ~-' Components (a) and (b) comprise the viscoelastic thickener and are as described previously in the first embodiment. The alkali metal hydro~ide is preferably potassium or sodium ; hydro~ide, and is present in an amount of between about 0.5 and 20% percent. The preferred alkali metal silicate is one having the-formula ~2O~SiO)n where M is an alkali metal and n is between 1 and 4. Preferably M is scdium and n is 2.3. The alkali metal silicate is present in an amount of about 0 to 5 percent. The preferred alkali metal carbonate is sodium carbonate, at levels of between about 0 and 5 percent.
About 1 to 10.0 percent hypochlorite is present, preferably about 4 to 8.0 percent.

In a third embodiment, a viscoelastic hypochlorite cleaning composition is provided and comprises, in aqueous solution (a) a quaternary ammonium compound;
(b) an organic counterion, and (c) a hypochlorite bleaching species.
~ . .
The composition of the third embodiment may have utility as a hard surface cleaner. Hypochlorite may also be incorporated into a drain opening composition, as previously described.
The thick solutions are clear and transparent, and can have higher viscosities than hypochlorite solutions of the art.
~ecause viscoelastic thickening is more efficient, less surfactant is needed to attain the viscosity, and chemical and physical stabili~y of the composition generally is better.
Less surfactant also results in a more cost-effective composition. As a hard surface cleaner, the viscoelastic rheology prevents the composition from spreading on hori~ontal sources and thus aids in protecting nearby bleach-sensitive surfaces. The viscoelasticity also provides the benefits o~ a thick syste~ e.~. increased residence time on nonhorizontal surfaces. Generally, ~he preferred ~uat for use with ., :.

: : . ~ . . . ............................ - - . . . .
-hypochlorite (or other source of ionic strength) is an alkyl trimethyl quaternary ammonium compound having a 14 to 18 carbon alkyl group, and most preferably the quat is CETAC.
Owing to the relatively high ionic strength of the hypochlorite, it is preferred that Rl, R2 and R3 be relatively small, and methyls are more preferred. In the presence of hypochlorite, the composition is most stable when no more than about 1.0 weight percent quat is present, although up to about 10 weight percent quat can be used.
Substituted benzoic acids are preferred as the counterion with 4-chlorobenzoic acid being more preferred. Most preferred are - mixtures of 4-chlorobenzoic acid or 4-toluic acid with a sulfonate counterion, such as sodium xylenesulfonate. In the presence of bleach, hydroxyl, amino, and carbonyl substituents on the counterion should be avoided. Table VI shows hypochlorite and viscosity stability for various formulations having mi~tures of counterions.

. -.. . .. .

-27- 1 3 2 5 q 6 Table VI. Stability at 120F.
X Remaining at 120 F
Counteri~n Counterion Viscos;ty NaOCl CETAC Viscosity ;~ No. WtX VtZ Name ~tZ Name cP lwk 2wklwk 2wk 1 0.50 0.20 BSA û.lO 4-NaA 206 75 75 2 0.5û 0.20 BSA 0.2û Benzoic Ac;d 136 95 75 3 0.50 0.20 8SA 0.15 SXS 135 74 74 4 0.50 0.05 4-C8SA 0.10 4-NeA 200 75 75 0.50 0.05 4-C8SA 0.10 8enzoic Acid 158 96 74 6 0.50 0.05 4-C8SA 0.30 Benzoic Acid 205 94 75 7 0.50 0.05 4-C8SA 0.15 SXS 82 76 76 8 0.3û 0.12 4-C8A 0.30 SXS 184 93 63 60 9 0.40 0.12 4-C8A 0.28 SXS 300 82 74 60 0.52 O.09 4-C8A 0.29 SXS 180 91 98 79 64 : 11 0.50 0.12 4 { 8A 0.28 SXS 346 99 12 0.50 0.15 4-C8A 0.35 SXS 413 93 67 59 13 0.62 0.09 4-C8A 0.29 SXS 235 85 85 76 60 14 0 72 0.04 4-C8Aû.29 SXS 316 77 76 78 62 0 30 0.05 NA 0.05 SXS 118 44 76 16 0.30 0.10 NA 0.10 SXS 120 48 - 76 17 0.48 0.21 SA None 280 0 Control None None 79 65 All for~u1as contain 5.2-5.8 wt. X sodium hypochlor;te, 1.6-1.8 wt. X sodium hydrox;de, about 4-5 wt. X sodium chloride, 0.25 wt, Z sod;um carbonate and 0.113 wt.Z of sodium silicate (Si02 / Na2O ~ 3.22).
V;scoS;t;eS were measured at 72 - 76 F with a 8rookf;eld rotov;scometer model LVTD
us;ng spindle # 2 at 30 rpm.
4-C8A . 4-Chlorobenzoic Ac;d -' 4-C8SA . 4-Chlorobenzenesulfonic Ac;d SXS . Sod;um Xylenesulfonate 2-C8A - 2-Chlorobenzoic Ac;d 8SA . 8enzenesulfonic Ac;d NA ~ Naphtho;c Acid SA - Sal;cylic Acid 4-N8A _ 4-Nitrobenzoic Ac;d - :' ' ' ' -. -. ,- ;' .- .:

-~- 1325q61 (-Table VII shows the mixture of carbo~ylate and sulfonate counterions results in a significant improvement in viscosity stability, as well as phase stability, over formulations of the art containing equal levels of hypochlorite. Formulas 1 and 2, are compositions of the present invention and retain . essentially all of their initial viscosity after two weeks at .- 106F, with formula 2 showing only a slight decrease after 12 weeks at 106F. By comparison, none of the formulations of the art retained even one-half of their initial viscosity ' ' ' : after 12 weeks at 106F.

~:

: 20 ~ . . , .. .. ,. ~ - . - - .... . . - .. .- .- . : : ... - .. :

- . : . . - . -~ :,- . :, :: .

.- - . - . - - . . . . . , . ~ :
- - . - . ~ . , : : :

-~9- 1 32596 1 . . ; , Table VII viscos;ty Stability Compared to Other Fonmulas :
Percent Viscosity Left Initial Thickening SystemViscosity Weeks at 106 f cP 1 2 4 8 12 1 32û lûl 99 N/A104100 .

.,.~
' , All formulas contain 4.5-5.8 wt.X of sodium hypochlorite, 1.5-1.8 wt.X of - sodium hydroxide, 3.5-4.6 wt.Z of sodium chlor;de, 0.25 wt.X of sodium carbonate, and 0.11-0.45 wt.% of sodiu0 silicate tSiO2/Na2O - 3.22).

Viscoslties were measured at 72-75 ~ with a 8rookf;eld rotovisco0eter model LVtû using cylindrical spindle #2 at 30 rpm.
,' .' . '.
~1) contains 0.05 wt.X Cetyltr;0ethylammonium Chlor;de, 0.12 wt.X
4-Chlorobenzoic acid and 0.35 wt.X Sodium xylene sulfonate.
i ~2) contains 0.62 wt.X Cetyltrimethylammon;um Chloride, û.09 wt.
4-Chloroben~o;c ac~d and 0.29 wt.X Sod;~m xylene sulfonate.
(3) contains û.97 wt.X Sodium lauryl sulfate, 0.30 wt.X Sodiu0 lauroyl sarcosinate and 0.30 wt.X Sodiu- lauryl ether sulfate.
30(4) contains 0.60 wt.X Myristyl/cetyldi0ethylamine oxide, 0.20 wt.% Capric acid and 0.10 ~t.X Lauric acid.
(5) contains 0.65 wt.X Myristyl/cetyldimethylamine ox;de and 0.20 wt.X Sodium alkylnaphthalene sulfonate.
(5) contA;ns 1.00 wt.X Myristyl/cetyldimetnylamine oxide, 0.25 wt.X Sod1um xylene sulfonate and 0.35 wt.X Disodium dodecyldiphenyl oxide di sul foaate.

,.
' ' '':

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A bleach source may be selected from various hypochlorite-producing species, for eYample, halogen bleaches selected from the group consisting of the alkali metal and alkaline earth salts of hypohalite, haloamines, haloimines, haloimides and haloamides. All of these are believed to produce hypohalous bleaching species in situ. Hypochlorite and compounds producing hypochlorite in aqueous solution are preferred, although hypobromite is also suitable. Representative hypochlorite-producing compounds include sodium, potassium, lithium and calcium hypochlorite, chlorinated trisodium phosphate dodecahydrate, potassium and sodium dicholoroisocyanurate and trichlorocyanuric acid. Organic bleach sources suitable for use include heterocyclic N-bromo and N-chloro imides such as trichlorocyanuric and tribromo-cyanuric acid, dibromo- and dichlorocyanuric acid, --and potassium and sodium salts thereof, N-brominated and N-chlorinated succinimide, malonimide, phthalimide and ~-naphthalimide. Also suitable are hydantoins, such as dibromo and dichloro.dimethyl-hydantoin, chlorobromodimethyl hydantoin, N-chlorosulfamide (haloamide) and chloramine (haloamine). Particularly preferred in this invention is sodium hypochlorite having the chemical formula NaOCl, in an amount ranging from about 0.1 weight percent to about 15 weight percent, more preferably about 0.2% to 10%, and most preerably about 2.0% to 6.0%.

Advantageously, the viscoelastic thic~ener is not diminished by ionic strength, nor does it require ionic strength for thic~ening. Suprisingly, the ~iscoelastic compositions of the present in~ention are phase-stable and retain their rheology ~ `
in solutions with more than a~out 0.5 weight percent ionizable salt, e.g., sodium chloride and sodium hypochlorite, '.
- , :

.

corresponding to an ionic strength of about 0.09 g-ions/Kg solution. Suprisingly, the composition rheology remained stable at levels of ionizable salt of between about 5 and 20 percent, corresponding to an ionic strength of between about 1-4 g-ions/Kg. It is expected that the viscoelastic rheology would remain even at ionic strengths of at least about 6 g-ions/Kg. Table VIII shows the effects of a salt on - viscosity and phase stability for a hypochlorite containing composition of the present invention.

':

, . . , .. : , . ... -. .. . , : ~ .; , .. .. . .

t 32596 1 Table VIII

Wei~ht Percent Formula 1 2 3 4 CETAC 0.50 0.50 0.50 0.50 4-Chlorobenzoic Acid0.13 0.13 0.13 0.13 Sodium Xylenesulfonate 0.32 0.32 0.32 0.32 Sodium Hypochlorite5.80 5.80 5.80 5.80 Sodium ~ydro~ide 1.75 1.75 1.75 1.75 Sodium Silicate 0.11 0.11 0.11 0.11 (SiO2/~a2O = 3.22) Sodium Carbonate 0.25 0.25 0.25 0.25 Sodium Chloridea 4.55 5.30 7.05 9.55 Ionic Strenath, g-ions/Kg 2.42 2.71 3.00 3.61 ViscositYb, cP
3 rpm 600 680 8201120 30 rpm 385 386 384388 Number of Phases 10 F lC lC

a. Includes salt from the manufacture of sodium hypochlorite.
b. Viscosities were measured at 72 F with a Brookfield rotoviscometer model LVTD using spindle # 2. -': ' C - Cloudy Optional Ingredients Buffers and pH adjusting a~ents may be added to adjust or maintain p~. Examples of buffers include the alkali metal phosphates, polyphosphates, pyrophosphates, triphosphates, tetraphosphates, silicates, metasilicates, polysilicates, carbonates, hydroxides, and mi~tures of the same. Certain -salts, e.~., alkaline earth phosphates, carbonates, hydro~ides, etc., can also function as buffers. It ma~ also -33~ 1 32596 ~

be suitable to use as buffers such materials as aluminosilicates (zeolites), borates, aluminates and bleach-resistant organic materials, such as gluconates, succinates, maleates, and their alkali metal salts. These buffers function to keep the pH ranges of the present invention compatable with the cleaning active, depending on the embodiment. Control of pH may be necessary to maintain -; the stability of the cleaning active, and to maintain the counterion in anionic form. In the first instance, a cleaning active such as hypochlorite is maintained above about pH 10, preferably above or about p~ 12. The counterions, on the other hand, generally don't require a pH higher than about 8 and may be as low as pH 5-6. Counterions based on strong acids may tolerate even lower pH's. The total amount of buffer including that inherently present with bleach plus any added, can vary from about 0.0% to 25~.
The composition of the present invention can be formulated to include such components as fragrances, coloring agents, whiteners, solvents, chelating agents and builders, which enhance performance, stability or aesthetic appeal of the composition. From about .01% to about .5% of a fragrancP such as those commercially available from International Flavors and ; Fragrance, Inc; may be included in any of the compositions of the first, second or third embodiments. Dyes and pigments may be included in small amounts. Ultramarine Blue (UMB) and copper phthalocyanines are examples of widely used pigments which may be incorporated in the composition of the present - invention. Suitable builders which may be optionally included comprise carbonates, phosphates and pyrophosphates, exemplified by such builders function as is known in the art to reduce the concentration of free calcium or magnesium ions in the aqueous solution. Certain of the previously mentioned buffer materials, e.g. carbonates, phosphates, phosphonates, polyacrylates and pyrophosphates also function as builders.

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1 ~2596t While described in terms of the presently preferred :
embodiment, it is to be understood that such disclosure is not to be interpreted as limiting. Various modifications and alterations will no doubt occur to one skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all such modifications and alterations as fall within the true spirit and scope of the invention.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of cleaning restrictions caused by organic materials in drain pipes comprising (a) introducing to a drain pipe having an organic restriction therein a drain opening composition comprising a drain opening active and a viscoelastic thickening system wherein the composition has a relative elasticity of greater than about 0.03 sec/Pa a delivery percentage of above about 75%, as determined by pouring a first quantity of composition through a second quantity of standing water and measuring an amount of undiluted product delivered, and a flow rate of less than about 150 mL/minute through a U.S.
230 mesh screen;
(b) allowing the composition to remain in contact with the organic restriction material to react therewith;
and (c) rinsing the composition and restriction away.

2. The method of claim 1 wherein the drain opening active is selected from the group consisting of acids, bases, oxidants, reductants, solvents, enzymes, detergents, thioorganic compounds, and mixtures thereof.

3. The method of claim 1 wherein the vicsoelastic thickener comprises a quatenary ammonium compound and an organic counterion.

4. The method of claim 3 wherein the quaternary ammonium compound is selected from the group consisting of compounds having the following structures:

(i) (ii) and;

(iii) mixtures thereof;

wherein R1, R2 and R3, are the same or different and are methyl, ethyl, propyl, isopropyl or benzyl, R4 is C14-18 alkyl, and R5 is C14-18 alkyl, and; an organic counterion is selected from the group consisting of alkyl and aryl carboxylates, alkyl and aryl sulfonates, sulfated alkyl and aryl alcohols, and mixtures thereof; and wherein the quaternary ammonium compound and organic counterion are present in an amount sufficient to thicken and result in a viscoelastic rheology.

5. The method of claim 4 wherein the composition comprises:
(a) 0.5 to 20 weight percent of an alkali metal hydroxide;
(b) 1 to 10 weight percent alkali metal hypochlorite;
(c) 0 to 5 weight percent alkali metal silicate;
(d) 0 to 5 weight percent alkali metal carbonate;
(e) 0.1 to 10 weight percent quaternary ammonium compound; and (f) 0.01 to 10 weight percent counterion.